repair doc tools and polish the docs code (#5038)

* set private access modifier

* repair doc build tools

* fix lit issues

* re-generate version index

package.json

@@ -12,6 +12,7 @@
     "webpack": "node ./node_modules/webpack/bin/webpack.js",
     "00": "echo -------------------------------------------- DOC  -----------------------------------------------",
     "00s": "",
+    "build-doc-tools": "tsc -p ./tools/doc/tsconfig.json",
     "markdownlint": "markdownlint ./docs",
     "docbuild": "node node_modules/typedoc/bin/typedoc --tsconfig lib/tsconfig.doc.json && node tools/doc/buildYamlSourceInfo.js docs/docs.json && node ./tools/doc/docProcessor.js",
     "license-checker": "license-checker --production  --failOn 'GPL' > licenses.txt",
@@ -126,10 +127,11 @@
     "@angular/compiler-cli": "^7.2.15",
     "@nrwl/nx": "7.1.1",
     "@nrwl/schematics": "7.1.1",
+    "@paperist/types-remark": "^0.1.3",
     "@types/hammerjs": "2.0.35",
     "@types/jasmine": "~2.8.3",
     "@types/jasminewd2": "~2.0.2",
-    "@types/node": "6.0.90",
+    "@types/node": "^12.7.3",
     "@types/selenium-webdriver": "^3.0.8",
     "ajv-cli": "^3.0.0",
     "bundlesize": "^0.17.2",
@@ -167,6 +169,7 @@
     "lite-server": "^2.4.0",
     "lodash.wrap": "^4.1.1",
     "markdownlint-cli": "^0.16.0",
+    "mdast": "^3.0.0",
     "mdast-util-compact": "^1.0.1",
     "mdast-util-heading-range": "^2.1.0",
     "mdast-util-toc": "^2.0.1",